Total number of residents = 20000
Total number of female residents = 12000
Total number of male residents = 8000

Let the number of females born in town T = x
Then the number of females not born in T = 12000-x
Let the number of males born in town T = y
Then the number of males not born in T = 8000-y
The question can now be rephrased to 'What is the value of ((x+y)/20000)*100 ?

(1) The number of female residents who were born in Town T is twice the number of male residents who were not born in Town T.

x=2*y. So, ((x+y)/20000)*100 = (3y)/200. Since we don't know the value of y, statement I is not sufficient to answer the question

(2) The number of female residents who were not born n Town T is twice the number of female residents who were born in Town T.

12000-x = 2x
3x = 12000
x = 4000
So, ((x+y)/20000)*100 = (4000+y)/200. Since we don't know the value of y, statement II is not sufficient to answer the question

From I and II

x = 2y = 4000, implies y = 2000.So, ((x+y)/20000)*100 = (4000+2000)/200 = 30%. So, Statement I + Statement II combined works great. IMO C

I think each statement is enough.

jrakhe wrote:I think each statement is enough.

Hi jrakhe,

Total population of T = 20,000
Total males = 8,000.
Total females = 12,000

Let number of males born in town T = M
Let number of females born in town T = F

Now, for two variables we will need two *distinct* equations.

Lets examine..

1) The number of female residents who were born in Town T is twice the number of male residents who were not born in Town T.

=> F = 2*(8000 -M)

2) The number of female residents who were not born in Town T is twice the number of female residents who were born in Town T.

=> (12000 -F) = 2*F

Thus, since 1.) and 2.) are distinct they will give unique value of M and F, from which the required % will be (M+f)/20000*100

Hope it helps!!

IMO:C

tofubeans wrote:63) A Town T has 20,000 residents, 60 percent of whom are female. What percent of the residents were born in Town T?

1) The number of female residents who were born in Town T is twice the number of male residents who were not born in Town T.

2) The number of female residents who were not born in Town T is twice the number of female residents who were born in Town T.

We are given that of the 20,000 residents in Town T, 20,000 x 0.6 = 12,000 are female, and thus 8,000 are male. We need to determine the percentage of residents who were born in Town T.

Statement One Alone:

The number of female residents who were born in Town T is twice the number of male residents who were not born in Town T.

We can let the number of male residents born in Town T = m, and the number of female residents born in Town T = f. Thus, (8,000 - m) males and (12,000 - f) females were not born in Town T.

From the statement, we see that f = 2(8,000 - m). However, we still cannot determine the percentage of residents who were born in Town T. Statement one alone is not sufficient to answer the question.

Statement Two Alone:

The number of female residents who were not born in Town T is twice the number of female residents who were born in Town T.

We can let the number of female residents born in town T = f. Thus, (12,000 - f) females were not born in Town T.

From the statement, we see that (12,000 - f) = 2f. Solving for f, we have:

3f = 12,000

f = 4,000

However, we still cannot determine the percentage of residents who were born in Town T, since we don't know the number of males who were born in Town T. Statement two alone is not sufficient to answer the question.

Statements One and Two Together:

Using both statements, we see that f = 2(8,000 - m) and f = 4,000. Thus:

4,000 = 2(8,000 - m)

4,000 = 16,000 - 2m

2m = 12,000

m = 6,000

So, 4,000 females and 6,000 males were born in Town T, which is 10,000 people.

Thus, 10,000/20,000 = 50% of the residents were born in Town T.

Answer: C